For example, an electric conductivity meter that measures electric conductivity of a chemical liquid is used in order to control concentration used for, for example, a semiconductor manufacturing process.
The electric conductivity meter comprises, as shown in the patent document 1, a pair of bar-shaped electrodes and an electrode support member that supports a pair of the above-mentioned electrodes, and is so configured that a pair of the electrodes project in a flow channel where a fluid such as a chemical liquid flows as to make a pair of the electrodes contact with the fluid.